ADAS’ compost trial results show fertiliser savings

Cereals exhibitor 2009

ADAS is focusing on results of a three-year project on compost use for agriculture and land restoration at Cereals, offering visitors a preview of before the final report is published in December.

The £3.4m landfill tax credit-funded project indictaes likely fertiliser savings from using compost and the longer-term benefits of using compost on soils. There have been 12 experiments in total in harvest years 2006, 2007 and 2008, mostly on winter wheat but also on oilseed rape and potatoes.

Green/food waste compost was applied either just once (autumn 2005) or each autumn. The crop response with and without compost, in combination with inorganic nitrogen at varying rates will be shown and also the effects of the compost on the soil quality – physical, chemical and biological properties.

ADAS experts on compost/waste management and soil science will be on the stand

Compost project facts:

  • Green/food composts are worth £10-12/t in terms of the crop nutrients supplied
  • Compost is a particularly good source of potassium
  • The longer term benefits of using compost to improve soil quality are even more significant, particularly for farmers on drought-prone sandy soils or heavy clay soils.
  • Leaching of nitrate over winter from compost is negligible because the nitrogen in compost only becomes available very slowly.
  • The experiments showed that when compost is applied crop yields with a lower rate of bag nitrogen are as good as with full rates.